Ensure test cluster classpath inputs have predictable ordering #43938
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Because we build test cluster distribution classpaths using a unordered set implementation, file order for otherwise identical sets can differ across build invocations. The result of this is different build cache keys and cache misses. To combat this we sort these collections so that we can ensure stable and predictable ordering given the same set of files. As an example, here's a build scan where the classpath is otherwise identical except for order.